Please help moving site

I hve read the instructions on this site, but I’m still unsure of the full process. My blog was built using a submain of my main domain for testing. I now want to move it to the root of my main domain.

One of the steps involves updating your .htaccess file for permalinks. My structure for permalinks is custon and has this code in the field:

/%category%/%postname%/

Do I have to manually edit this file? and if so, what code do I put there and where?

Also it says not to vist your blog after you’ve updated your wordpress address and blog address in the setting panel. But this site is live, and someone could visit a page. Should I delete all files except for the admin folder to prevent anyone visiting the blog?

As mentioned, the blog will be on the same server, jsut using the main domain. Any help you can provide so this goes smoothly is greatly appreciated. I’m really new to this.

Thanks,
Doug